->''"If I were not mad, I could have helped you. Whatever you had done, I could have pitied and protected you. But because I am mad, I hate you. Because I am mad, I have betrayed you. And because I'm mad, I'm rejoicing in my heart, without a shred of pity, without a shred of regret, watching you go with glory in my heart!"''
-->-- '''Paula Alquist''' denouncing her husband

Based on a 1938 play by Patrick Hamilton, ''Gaslight'' is a 1944 psychological-thriller directed by Creator/GeorgeCukor and staring Creator/IngridBergman in her first Oscar-winning performance.

She plays Paula, a young girl who lived with her aunt, a famous opera singer. One day, the aunt is suddenly murdered and robbed by the mysterious Sergius Bauer, leaving Paula alone. After studying abroad for the ten years since the incident, she returns to England with a new husband, Gregory (Creator/CharlesBoyer). But shortly afterwards, Gregory suddenly starts going out of his way to MindRape Paula.

Can Paula find out the reason for her husband's cruelty? Can a sympathetic UsefulNotes/ScotlandYard officer (Creator/JosephCotten) save the day?

A very-young Creator/AngelaLansbury made her film debut as the quirky maid Nancy; the performance won her an Academy Award nomination for Best Supporting Actress.

!!This movie provides examples of:

* AlliterativeName: Alice Alquist.
* AloneWithThePsycho: Paula being confronted by Gregory in the film's finale, while Brian is not around to help her.
* BitchInSheepsClothing / DevilInPlainSight: Gregory. Paula is a HorribleJudgeOfCharacter to not notice it.
* BoundAndGagged: Gregory, after Brian and the constable overpower him.
* CatchPhrase: Miss Thwaites' "Well!"
* ChekhovsGun:
** One of Paula's aunt's stage gloves, given to an unnamed admirer who turns out to have been Cameron as a boy.
** The costume Alice Alquist is wearing in her portrait is where she hid the jewels.
* DeathByChildbirth: Paula's mother died when she was born, though Gregory later twists the story to serve his agenda.
* DecompositeCharacter: The detective from the original play is split into two characters, Brian and Ms. Thwaites.
* TheDogBitesBack: Paula charging Gregory when latter is BoundAndGagged.
* DomesticAbuse: One of the most iconic examples in fiction, as Gregory bullies, isolates, and manipulates Paula to the point of madness.
* DrivenToMadness: Gregory pulls no punches in order to convince Paula she's going mad.
* DrosteImage: Gregory holding Alice Alquist's costume in front of a painting of the singer wearing said costume.
* AFoggyDayInLondonTown: The film uses this as OminousFog to establish mood, like when Paula is being led away from the house after her aunt has been murdered, or later, when her evil husband Gregory is skulking through the streets and alleyways.
* FourthDateMarriage: Invoked by Gregory to push his agenda. He starts talking about marriage already after two weeks of knowing Paula.
* FrenchJerk: In the 1944 film, the villainous Gregory is played by Charles Boyer, who uses his natural accent. Possibly subverted, as Gregory's real name is Sergis Bauer, and is apparently from Prague, so it could be an affectation.
* {{Gaslighting}}: TropeMaker and TropeNamer.
* GunStruggle: Between Gregory and Brian. Nobody gets harmed though.
* HauntedHouseHistorian: The neighbor is extremely knowledgeable about the murder mystery at the house.
* HeKnowsTooMuch: Gregory tries to make Paula believe she is an UnreliableNarrator, in order to make her deny she ever saw that letter which tied him to the murder case.
* HellIsThatNoise: The noise from the attic is driving Paula crazy.
* HiddenInPlainSight: How Alice hid the jewels that the tsar gave her, the ones Gregory is hunting for--on the costume she wore to the opera, amidst all the fake jewelery she wore for her performance.
* HoistByHisOwnPetard: As the page quote proudly demonstrates, Paula proudly turns Gregory's scheme to drive her to madness back on him.
* HorribleJudgeOfCharacter: Paula is a manipulated victim, carrying the IdiotBall of taking Gregory for a well-meaning husband.
* MacGuffin: The jewels.
* ManipulativeBastard: Gregory, who sought Paula out and married her so he could get access to her house and find the jewels.
* MaybeEverAfter: At the end, Brian the detective tells Paula that he'll come by later and help her get past her trauma.
* MindRape: Gregory's mind games that he uses to convince Paula she's going insane.
* MoodSwinger: Gregory can go from barely contained fury to cooing affection in an instant. It's probably deliberate, to keep Paula off-balance, but Gregory doesn't really seem like Mister Stability himself.
* MrExposition: The neighbor being a HauntedHouseHistorian and the police captain dropping {{Info Dump}}s about the missing jewels.
* NeverMyFault: Gregory never for a moment lets Paula entertain the idea that he may be mistaken; ''she'' must be mad. At the end, Gregory insists that he and Paula could have been happy together were it not for her aunt's jewels. This is a man who has married a woman ''explicitly to drive her insane'' so she'd be committed, and murdered her aunt for the aforementioned jewels. Paula's not impressed.
* NosyNeighbor: Miss Thwaites.
* NotEvenBotheringWithTheAccent: Joseph Cotten using his own courtly Virginia accent to play a Scotland Yard detective.
* OminousFog: Lots of it around the neighborhood as Paula is led away from the house after her aunt's murder, and lots more later, when Gregory is skulking through the alleys.
* OneLinerNameOneLiner: Brian to the cop: "I don't know, Williams. I don't know."
* ParentalAbandonment: Paula's mother suffered DeathByChildbirth and she never met her DisappearedDad, so she grew up with her aunt, the famous singer Alice Alquist.
* PoliceAreUseless:
** Played straight with General Huddleston who tries hard to keep the lid on the murder case.
** Averted with Constable Williams who helps Brian solve the case and also later when both overpower Gregory.
* PosthumousCharacter: Alice Alquist, opera singer, lover to a tsar, owner of valuable jewels that Sergis Bauer is determined to find.
* ReallyGetsAround: Nancy the slutty maid, portrayed as explicitly as possible in 1944.
* TheRemake: This was the second film adaptation of the play; the first was a British film made in 1940. MGM ''tried to buy and burn up all the negatives'' of the 1940 version in order to avoid any competition with its film. They failed, and the earlier version survives today (it even wound up as an extra on the DVD).
* ServileSnarker: Nancy.
* SleepingSingle: Paula and Gregory have separate rooms--of course, given Gregory's ulterior motives, this makes sense.
* TapOnTheHead: How Gregory is ultimately subdued in the 1940 version.
* TerribleTicking: One of Gregory's tricks on Paula.
* VictorianLondon
* [[YouCanSeeThatRight You Can Hear That, Right?]]: Paula asking the cook to confirm the [[HellIsThatNoise noises coming from the attic]]. Too bad, latter is hearing-impaired.